Rotary internal combustion engine

ABSTRACT

A sliding abutment rotary internal combustion engine with dual eccentric identically shaped rotors on a common shaft is described. The angle of eccentricity of the first rotor from the second rotor is 180* such that when the first rotor is inletting and then compressing a fuel-air mixture through a first 360* of rotation of the shaft, the second rotor is providing power by the combustion of a fuel-air mixture and then exhausting the combustion products through the second 360* of rotation of the shaft. A complete engine cycle is completed in 720* of shaft rotation. Valved conduit means are used for fuel-air inlet and combustion products exhaust to chambers formed by sliding abutment, engine housing and rotor. Particularly preferred valve actuating means for the rotary engine are described.

United. States Patent Lay [4 1 Sept. 2, 1975 ROTARY INTERNAL CONIBUSTIONENGINE Inventor: Joachim E. Lay, 1749 Ridgewood,

East Lansing, Mich. 48823 Filed: Nov. 7, 1973 Appl. No.: 413,626

US. Cl. 123/8.07; 123/845; 418/60; 418/246 Int. Cl. F02B 53/06 Field ofSearch 123/807, 8.45; 418/60, 418/244, 246

References Cited UNITED STATES PATENTS 3/1908 Walker 418/246 X 1/1934Thomas 123/845 X 7/1965 Bentele..... 123/845 X ,093 3/1967 Castelet123/845 FOREIGN PATENTS OR APPLICATIONS 10/1928 United Kingdom 123/845Primary ExaminerWi1liam L. Freeh Assistant ExaminerMichael Koczo, Jr.

Attorney, Agent, or Firm-Miller, Morriss, Pappas &

McLeod [57 ABSTRACT A sliding abutment rotary internal combustion enginewith dual eccentric identically shaped rotors on a common shaft isdescribed. The angle of eccentricity of the first rotor from the secondrotor is 180 such that when the first rotor is inletting and thencompressing a fuelair mixture through a first 360 of rotation of theshaft, the second rotor is providing power 7 by the combustion of afuel-air mixture and then exhausting the combustion products through thesecond 360 of rotation of the shaft. A complete engine cycle iscompleted in 720 of shaft rotation. Valved conduit means are used forfuel-air inlet and combustion products exhaust to chambers formed bysliding abutment, engine housing and rotor. Particularly preferred valveactuating means for the rotary engine are described.

9 Claims, 29 Drawing Figures PATENTED 21975 SHEET 1 BF 5 ROTARY INTERNALCOMBUSTION ENGINE SUMMARY OF THE INVENTION The present invention relatesto a sliding abutment rotary internal combustion engine wherein spacedapart, dual eccentric rotors are provided on a common shaft such thatwhile one rotor is inletting and then compressing a fuel-air mixturethrough a first 360 of rotation of the shaft, the other rotor isproviding fuelair combustion and then combustion products exhaustthrough the second 360 of rotation of the shaft. Chambersformed by therotors, abutment and engine hous-.

ing are fired in sequence around the first rotor housing and then insequence around the second rotor housing through 720 of rotation of theshaft.

PRIOR ART A rotary internal combustion engine has inherent advantagesovera reciprocating internal combustion engine, mainly because theenergy released by the combustion can be converted directly intorotational motion of the shaft mounting the rotor. In fact, the idea ofa rotary engine goes back several centuries and actually pre-dates theinvention of the reciprocating engine. However, the quest for a rotaryengine which is simple and inexpensive to produce has met with limitedsuccess so far, and only in a few cases such as the Wankel engine havesuch engines been mass produced. Although many rotary engines have beenconceived (the literature abounds with ingenious and complicated designsfor rotary combustion engines), they generally are difficult andexpensive to produce.

Sliding abutment rotary combustion engines are well known to the priorart. For instance, they are shown in US. Pat. Nos. 2,155,775; 2,409,141;3,155,081; and 3,280,804. In these rotary engines, equally spaced camlobes on the rotor move the sliding abutments. In others, such as shownin US. Pat. Nos. 3,164,139 and 3,539,280, a single eccentric rotor isdescribed. In all of these rotary engines there is no valving for theexhaust, since the fuel-air mixture moves the rotor into the position ofignition and then exhausts within 360 of rotation of the rotor. In orderto balance these engines, the rotor must be counterbalanced opposite theeccentricity, usually by another balancing eccentricity on the samerotor.

US. Pat. No. 2,155,775 describes a dual rotor unit where both rotors arefired simultaneously 180 apart and repeatedly during 360 of revolutionof the rotor shaft. A complex air injection system is provided whereincompressed air is channeled to the chamber where the firing is to takeplace from three other chambers provided on each rotor. Balance isachieved by using dual rotors on the same shaft; however, the enginewould be difficult and expensive to manufacture. US. Pat. No. 2,409,141also describes a single rotor with compressed air injection fromopposite chambers with dual sequenced firing.

US. Pat. No. 3,155,081 shows multiple sequenced firing in 360 of rotorshaft rotation of the rotor. A lever is compressed onto the surface of abalanced rotor to compress the fuel-air mixture prior to firing. US..Pat. No. 3,280,804 shows multiple sequenced firing in 360 of rotorshaft rotation wherein air-fuel mixture ignition system is provided inthe rotor itself, The compressed air-fuel mixtureis provided inside therotor by means of ports and the fired mixture is ported onto the surfaceof the rotor adjacent two opposing lobes. US. Pat. No. 3,539,280 alsoshows multiple sequenced firing through 360 of rotation the use of acentral air inlet and usually fuel exhaust through an eccentric rotor.

Scientific American, Volume 220, No. 2, February 1969 (pages to 99)describes a number of rotary engines. Further, Alternatives to theInternal Combustion Engine (1972) by R. U. Axres and R. P. McKenna pages1 19 to describes recent developments in such engines. All are similarto the engines described above in that the cycles of fuel inlet,compression combustion and exhaust are completed at least once in 360 ofrotor shaft rotation. These rotary engines are also difficult andexpensive to build even when conventional valves are used. Further,means for fuel-air inlet or fuel-air compression is usually eithercomplex or uncertain in operation. The engine rotors are difficult tobalance and build and the rotors at high revolutions tend to overruntheir safe limits because of their momentum.

It is therefore an object of the present invention to provide a rotaryengine which is simple and inexpensive to build. Further still, it is anobject of the present in vention to provide an engine with positivefuel-air compression and wherein the fuel-air mixture is inletteddirectly into each firing chamber. Further still, it is an object of thepresent invention to provide an engine which has positive and easilyregulated fuel inlet and combustion exhaust. Further still, it is anobject of the present invention to provide an engine where the rotor hasless of a tendency to overrun the safe revolution limit. Also providedis a unique and simplified valve actuating means which accomplishesfuel-air inlet and exhaust outlet. These and other objects will becomeincreasingly apparent to those skilled in the art and in particular byreference to the drawings. 1

IN THE DRAWINGS FIGS. 1 and 1a, in front and side views respectively,schematically illustrate a shaft with two eccentrically mounted rotorswith their maximum eccentricity 180 apart.

FIGS. 2 and 2a, in a cross-section front and side view respectively,schematically illustrate the shaft and dual rotors mounted in a housingwhich has sliding abutments contacting the rotors.

FIG. 3, in a cross-sectional view of one rotor within its housing,schematically illustrates an assembled individual chamber or compartmentwith a spark plug and valves.

FIGS. 3a and 3b show the housing of each rotor being divided intoseparate compartments, labeled compartment A, compartment B, compartmentM. The intake and exhaust valves in each compartment are labeledrespectively as A,, A,., 3,, B M M FIGS. 4 through 7, schematicallyillustrate the two complete revolutions of one of the dual rotors toproduce the engine cycle wherein FIG. 4 shows fuel-air intake, FIG. 5compression, FIG. 6 combustion and FIG. 7 exhaust.

FIG. 8, in an end view with a partial section of one compartment,illustrates the preferred rotary internal combustion engine of thepresent invention and particularly illustrates the details ofthemounting of the valve means in the housing.

FIG. 9, in a cross-sectional view of the engine of FIG. 8 along line8--8, illustrates the valve actuating means mounted between the rotorson the crankshaft and particularly illustrates four cam surfaces on' aring gear.

FIG. 10 is a cross-section view of the ring gear, particularlyillustrates the planetary gearing to reduce the rate of rotation of thevalve actuating ring gear to onehalf that of the crankshaft and rotors.It also shows the profile of one cam surface, which actuates the intakevalves A 13,, C,, D,-, E,, and F,-.

FIG. 10a shows the profile and position of the cam surface, whichactuates the exhaust valves A B C D,., E,,, and F...

FIG. 10b shows the profile and position of the cam surface, whichactuates the intake valves K,, L M,, G H and 1,.

FIG. 100 shows the profile and position of the cam surface, whichactuates the exhaust valves K L M,,, G,,, H and J...

GENERAL DESCRIPTION The present invention relates to the design of arotary internal combustion engine using an eccentric rotor and slidingabutment to form chambers for compression and then combustion with valveand conduit means for fuel-air intake and products exhaust comprisingtwo identically shaped rotors eccentrically mounted on a common shaftwith the maximum eccentricity spaced 180 from each other; slidingabutment resiliently mounted in each of the housings for continuouscontact with the rotors throughout the revolution of the shaft so as toform sealed compression and then combustion chambers with the rotors;and fuel-air ignition means in each compression combustion chamberwherein during operation each of the chambers on one of the rotors isproviding in sequence a fuel-air mixture through the inlet valve conduitmeans and then fuel-air compression through 360 of rotation while theother of the rotors is providing in sequence fuel-air combustion andthen combustion products exhaust through the exhaust valve means througha second 360 of rotation.

The method of providing rotation of a shaft in a rotary internalcombustion engine housing with two spaced apart identically shapedrotors mounted eccentrically on the longitudinal axis of the shaft suchthat the radius of eccentricity from the longitudinal axis of one rotoris 180 from the same radius of the other rotor, with valved conduitmeans for fuel air inlet and combustion products exhaust outlet and withat least one sliding abutment forming a sealed compression andcombustion chamber between each rotor and its housing which comprises:providing a fuel-air mixture through the valved conduit fuel inlet meansto each chamber on the first rotor in sequence through 360 of rotationas the radius of maximum eccentricity passes each inlet at a trailingsurface of the rotor and then to the second rotor in the same sequencethrough 360 of rotation; compressing the fuel-air mixture between thefirst rotor, abutment and housing in sequence through the 360 of shaftrotation in step (a) using the power produced by the simultaneouscombustion of a compressed fuel-air mixture between the second rotor,abutment and housing; igniting the compressed fuel-air mixture betweenthe first rotor, abutment and housing on the trailing surface of therotor thereby providing the power for rotating the shaft a second 360 tocompress fuel-air mixture in the compartment formed by the second rotor,abutment and housing; and exhausting the combustion products from theleading surface of the first rotor upon completion of the second 360 ofrotation, wherein each of the chambers on one of the first rotor isprovided in sequence with a fuel-air mixture through the inlet valvedconduitmeans and then fuel-air compression while the second rotor isproviding in sequence fuel-air combustion and then combustion productsexhaust through the valved conduit means for a total of 720 of rotationof the shaft.

The rotary engine is illustrated in FIGS. 1 to 3 and consists of a shaft10 having a longitudinal axis of rotation 11 with two eccentricallymounted rotors 13 and 14 provided in a cylindrical casing or housing 15(FIG. 2) in which it rotates. The two rotors, l3 and 14 and thecrankshaft, 10, are shown in FIGS. 1 and 1a with the radii of maximumeccentricity 13a and 14a apart. The assembled engine, with the casing 15and end plates 18 and 18a included, is schematically shown in FIGS. 2,2a and 3. The broken lines show the rotor The relative positions of eachrotor 13 and 14 in the casing 15 is shown in FIGS. 2 and 3. Inside eachof the casings 15 are sliding abutments 16, held by springs 17 againstthe rotors l3 and 14. As shown, there are six abutments 16 per rotor 13and 14, thus forming six separate compartments or chambers which arespaced 60 apart.

Each compartment 19 contains air-fuel inlet and exhaust valve means,preferably a conventional intake valve 20 and an exhaust valve 21. Aspark plug 22 as shown in FIG. 3 can be used or other igniting meanssuch as glow plugs or heated tubes (not shown) can be used instead. Thevalves 20 and 21 are located adjacent to the abutments 16. As shownparticularly in FIGS. 30 and 3b, the valves 20 and 21 are lettered A toM in the firing sequence with subscripts (i) for intake and (e) forexhaust.

The operation of the rotary engine can be understood by reference to theevents taking place in one of the compartments 19 of FIG. 3 as shown inFIGS. 4 to 7 for one rotor. In FIG. 4a, the rotor .13 is in the positionshown at the beginning of the sequence of operations, just as it sweepspast the intake valve 20. The radius of eccentricity 13a of the rotor 13from the longitudinal axis 11 along the shaft 10 compresses the abutment16, while at the same time, the valves 20 and 21 are open. Consider thesweep as it reaches the intake valve to be the 0 of shaft 10 rotationwith the intake valve 20 open. A fresh charge of fuel and air is aboutto be swept into the chamber 19 on the trailing side of the rotor 13,while on the leading side of the rotor 13, discharge of the exhaustgases is being completed through the still open exhaust valve 21. Theintake process takes place as the shaft 10 rotates from 0 to 180. Atthis point (one-half a revolution of the crankshaft 10), the fuelairintake is completed, the intake valve 20 closes, and the fuelcompression process begins. The shaded area in FIGS. 40 to 4d denotesthe volume of air-fuel mixture 23 drawn in.

From-180 to 360 of shaft 10 rotation, fuel-air compression takes place,with both intake and exhaust valves 20 and 21 being closed. This isshown in FIGS. 5a to 5d, where the shaded area 24 (representing thevolume of trapped fuel and air), becomes smaller and smaller. Thecompression process 24 continues past 360, and at400 of shaft 10rotation, the spark plug 22 tires, whereupon the gas expansion 25 orpower stroke begins. This is shown in FIGS. 6a to 6d. The gas expansion25 is completed at 540.

At 540, the exhaust valve 21 opens, and discharge of the exhaust gases26 begins. Exhaust proceeds from 540 of shaft 10 rotation, through 720,to 40 (new cycle position). At 720 of shaft 10 rotation (2 revolutions),the intake valve opens to begin a new cycle, while the exhaust valve 21stays open to 40 to allow full rejection of the exhaust gases 26. Theexhaust process is shown in FIGS. 7a to 7d.

From the above description of the events shown in FIGS. 4 to 7 it isseen that an entire cycle, comprising intake, compression,combustion-expansion, and exhaust, takes place in two revolutions of theshaft 10. For this reason, two rotors 13 and 14, mounted with the radiiof 13a and 14a eccentricity 180 apart on a shaft 10, are specified perengine.

For an engine which basically makes use of two rotors 13 and 14, thefiring sequence follows the order of rotation of one rotor 13 and thenthe other rotor 14. That is, during a given revolution of the crankshaft10, all the chambers 19 surrounding the first rotor 13 fire one afterthe other through 360, while the chambers 19 surrounding the secondrotor 14 perform their tasks of intake and compression. During the nextrevolution through 360, all the chambers 19 surrounding the second rotor14 fire one after the other, while the chambers 19 surrounding the firstrotor 13 perform their tasks of intake and compression. A power strokeoccurs at every 60 of crankshaft 10 rotation in the preferred engine.The engine shown in FIGS. 1 to 7 is thus like a twelve cylinderreciprocating piston engine as to the number of firing chambers. Thetwelve chambers 19 assures a uniform torque output and a smoothoperation of the engine.

SPECIFIC DESCRIPTION FIGS. 8, 9 and 10 show a preferred rotary engine,such as illustrated in FIG. 3, in considerably more detail. Theeccentric rotors 110 and 111 are each confined in cylindricallycross-sectioned housings 112 and 113. Six (6) sliding abutments 109 withsprings 108 are provided in each of the housings 112 and 113. The rotors110 and 111 are mounted on a shaft 114 held in position by keys 115,116, 117 and 118, mounted in key ways between the rotors 110 and 111 andshaft 114. The construction engine in the two housings 112 and 1 13 isidentical except that the radii of eccentricity of the rotors 110 and111 are 180" around the central axis 107 of the shaft 114. Six sparkplugs 119 are mounted through the housing 112 and correspondinglythrough housing 113 (not shown). Six tapered head intake valves 120 aremounted in each of the housings 112 and 113 on one side of each of thespark plugs 119 so as to open towards the center 107 of the shaft 114and to close on seats 121 in conduits 122 and 123. Six tapered headexhaust valves 124 are mounted in the housings 112 and 113 on the otherside of the spark plugs 119 so as to open towards the center 107 of theshaft 114 and to close on seats 125. The housings 112 and 113 are closedby end plates 126, 127, 128 and 129 using bolts 130. The engine hasmounting plates 131. Ball bearings 132, 133, 134 and 135 (FIG. 9) areprovided in-recesses in the inside of end plates 126, 127, 128 and 129in contact with the sides of the rotors 110 and 111.

All of the valves and 124 are provided with identical compressed, coilsprings 136 and keepers 137 such that end portions 138 and] 139 of thevalves 120 and 124 respectively are exposed. The valve ends 138 and 139are acutated by rocker arms or levers 140 and 141 pivotally mounted at142 on the housing 112 by fork mounts 143.-Corresponding rocker arms140a and 141a are mounted on housing 113. The ends of the rocker armsare forked for rollers 145, mounted on pins 146. The roller 145 and arms140 and 141 are actuated by cam surfaces 151, 152, 153, and 154 on aring gear 150.

The ring gear is positioned between the rotors 110 and 111 and'supportedby opposing inside rotor closing plates 128 and 129 mounted on thehousings 112 and 113 respectively. The outsides of the plates 128 and129 support a planetary gear mechanism for driving the ring gear 150 asparticularly shown in FIGS. 9 and 10.

A central driving gear 147 is mounted on the shaft 114 by key 148. Thesides of the gear 147 bear on the outside of the plates 128 and 129.Three planetary driven gears 149 are rotatably mounted on the plates 128and 129 in contact with the gear 147 on a shaft 157 which is recessedinto plates 128 and 129 so as to be l20 apart. The planetary gears 156are in contact with the gears 149 and the inside of the ring gear 150and are also spaced 120 apart. Ball bearings are recessed into the endplates 128 and 129 for sliding contact with the sides of the ring gear150.

The four separate cam surfaces 151, 152, 153 and 154 on the outside ofthe ring gear 150 actuate the opening and closing of the valves 120 and124 by means of rocker arms 140, 140a, 141 and 141a as shown inFIG. 9.Rollers 145 each ride on one cam surface 151 to 154 on ring gear 150. Asthe shaft 114 and ring gear 150 rotate, the rocker arms 140, 140a, 141and 141a cause the valves 120 and 124 to open and close. Since theengine has 24 valves altogether, it is desirable to have a maximumnumber of valves 120 and 124 being driven from a given cam surface 151to 154. From the planetary gear arrangement shown in FIG. 10, it can beseen that the ring gear 150 revolves in the same direction as the rotors110 and 111. Also, because of the ratio of the diameter of the ring gear150 to the central gear 147, the ring gear 150 rotates at half theangular speed of the shaft 114. Thus, a complete cycle of events isaccomplished in two revolutions (720 of the shaft 114 and one revolution(360) of the ring gear 150. This enables the profile of the cam surfaces151 to 154 to be easily determined. For example, the intake process inchamber A takes place between 0 and 180 rotation of shaft 114. Since thering gear 150 rotates at half the shaft speed, cam surface 151 will havea dwell (the raised portion corresponding to the opened valve position)from 0 to 90. All the rollers actuating intake valves A,-, B,-, C,-, DE,, F, will ride on this surface. Cam surface 151 is shown in FIG. 10.

Similarly, the exhaust process in chamber A takes place between 540 and40 of shaft 114 revolution, and therefore cam surface 152 will have adwell from 270 to 20 as shown in FIG. 10a. All the rollers actuatingexhaust valves A B C,., D E,., P, will ride on this surface. Likewise,the profile of cam surface 153 actuating the intake valves K,-, L,-,M,-, G,, H,-, J,- is arrived at and shown in FIG. 10b, and the profileof cam surface 154 actuating exhaust valves K,., L.., M G. H... .L. isarrived at and shown in FIG. 100.

As can readily be seen from the foregoing description, the preferredrotary engine operates with valving to control fuel-air inlet andexhaust products outlet. The valving shown by FIGS. 8 to 10 ispreferred; however, it will be appreciated that other conventional valveactuating means or other valving means such as rotatable cylindricalported internal sleeve valves in mating contact with the internal wallsof the cylindrical housings 112 and 113 can be used as is well known tothose skilled in the art.

I claim:

1. A four-cycle rotary internal combustion engine which comprises:

a. a shaft having spaced apart bearing surfaces separating two sectionsof the shaft around a longitudinal axis for journaled rotation of theshaft;

two spaced apart identically shaped rotors mounted on the sections ofthe shaft between the bearing surfaces and eccentrically mounted oncrankshaft such that the radius of maximum eccentricity from thelongitudinal axis for the shaft of one rotor is 180 from the otherrotor;

c. dual housings mounting the shaft for journaled rotation of the rotorswith spaced apart surfaces from the radii of maximum eccentricity of therotor around the axis of rotation of the shaft;

d. at least two sliding abutments resiliently mounted in each of thehousings for continuous contact with the rotor through 360 of revolutionof the shaft so as to form sealed compartments with the rotors;

e. valved conduit means for air and fuel inlet and combustion productsexhaust outlet in each of the compartments formed by the abutments androtors, the valves extending to each compartment around the rotorshaving a head seating in the conduits in the housing for closure andhaving a shaft mounting the head and extending through and from thehousing, with external compressed coil springs mounted on the shafts andhousings to seat the valves;

means for actuating the valves at the extension of the shaft from thehousing including cam actuated levers mounted on the housing so as topivot and depress each valve shaft in sequence, wherein the camming ofthe levers is provided by four cam surfaces for independent inlet andoutlet valve opening around each rotor which are mounted between therotors and geared to the rotor shaft so as to rotate at one-half therate of rotation of the rotor shaft and wherein the cam surface rotationis regulated by a driving gear mounted on the shaft and multiple drivengears rotatably mounted to drive a ring gear bearing the cam surfaces;and

g. openings to each of the compartments for fuel-air ignition meanswhich are provided in each compartment wherein during operation of theengine one of the compartments on a first rotor provides in sequencefuel-air inlet through the fuel inlet valve means and then fuel-aircompression through 360 of shaft rotation while the second rotor isproviding in sequence fuel-air combustion and then combustion productsexhaust through the exhaust valve means and then the sequence isreversed during two complete revolutions of each rotor.

2. The rotary engine of claim 1 wherein the surfaces in the housing arecylindrically shaped.

3. The rotary engine of claim 1 wherein the ignition means openings areadapted for spark plugs.

4. The rotary engine of claim 1 wherein the rotors have a cylindricalcross-section.

5. The rotary engine of claim 2 wherein there are six sliding abutmentsso as to provide six sealed compartments around each rotor.

6. The rotary engine of claim 1 wherein the driven gears are journaledby opposing outside portions of the housing.

7. In a rotary engine using two identically shaped rotors eccentricallymounted on a common shaft in two separate housings with the maximumeccentricity spaced 180 from each other; at least two sliding abutmentsresiliently mounted in each of the housings for continuous contact withthe rotors throughout the revolution of the shaft so as to form sealedcompression and then combustion chambers with the rotors; and fuel-airignition means in each compression combustion chamber wherein duringoperation each of the chambers on one of the rotors is providing insequence a fuel-air mixture through an inlet valved conduit means andthen fuel-air compression through 360 of rotation while the other of therotors is providing in sequence fuel-air combustion and then combustionproducts exhaust through an exhaust valved conduit means through asecond 360 of rotation, wherein the inlet and exhaust valves have ashaft extending through and from the housing and wherein means foractuating the valves at the extension of the shaft from the housing isprovided to open the valves the improvement which comprises:

a. means for actuating the valve shafts including cam actuated leversmounted on the housing so as to pivot and depress each valve shaft insequence; and

b. four cam surfaces camming the levers for independent inlet and outletvalve opening around each rotor which are mounted between the rotors andgeared to the shaft so as to rotate at one-half the rate of rotation ofthe rotor shaft, wherein the cam surface rotation is regulated by therotation of the shaft by means which drive a ring bearing the camsurfaces.

8. The rotary engine of claim 7 wherein the cam surface rotation isregulated by a driving gear mounted on the shaft and multiple drivengears rotatably mounted to drive a ring gear bearing the cam surfaces.

9. The rotary engine of claim 7 wherein the driven gears are journaledby opposing outside portions of the housings.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,902,464 Dated September 2, 1975 Inventor(s) Joachim E. Lay

It is certified that error appears in the above-identified patent andthat said Letters Patent are hereby corrected as shown below:

Column 1, line 27, after "as" insert --With--.

Column 1, line 41, after "moves" insert --with--.

' Column 3, line 1, after "a" insert side--.

Column 3, line 48, insert a "hyphen" between fuel and air.

Column 8, line 13, Claim 5, change Claim 2" to read -Claim 1--.

Sign! and Scaled this second Day of December 1975 [SEAL] Attest:

RUTH C. MASON C. MARSHALL DAMN Arresting Officer ('ommissiontr afPaIenlsand Trademarks

1. A four-cycle rotary internal combustion engine which comprises: a. ashaft having spaced apart bearing surfaces separating two sections ofthe shaft around a longitudinal axis for journaled rotation of theshaft; b. two spaced apart identically shaped rotors mounted on thesections of the shaft between the bearing surfaces and eccentrIcallymounted on crankshaft such that the radius of maximum eccentricity fromthe longitudinal axis for the shaft of one rotor is 180* from the otherrotor; c. dual housings mounting the shaft for journaled rotation of therotors with spaced apart surfaces from the radii of maximum eccentricityof the rotor around the axis of rotation of the shaft; d. at least twosliding abutments resiliently mounted in each of the housings forcontinuous contact with the rotor through 360* of revolution of theshaft so as to form sealed compartments with the rotors; e. valvedconduit means for air and fuel inlet and combustion products exhaustoutlet in each of the compartments formed by the abutments and rotors,the valves extending to each compartment around the rotors having a headseating in the conduits in the housing for closure and having a shaftmounting the head and extending through and from the housing, withexternal compressed coil springs mounted on the shafts and housings toseat the valves; f. means for actuating the valves at the extension ofthe shaft from the housing including cam actuated levers mounted on thehousing so as to pivot and depress each valve shaft in sequence, whereinthe camming of the levers is provided by four cam surfaces forindependent inlet and outlet valve opening around each rotor which aremounted between the rotors and geared to the rotor shaft so as to rotateat one-half the rate of rotation of the rotor shaft and wherein the camsurface rotation is regulated by a driving gear mounted on the shaft andmultiple driven gears rotatably mounted to drive a ring gear bearing thecam surfaces; and g. openings to each of the compartments for fuel-airignition means which are provided in each compartment wherein duringoperation of the engine one of the compartments on a first rotorprovides in sequence fuel-air inlet through the fuel inlet valve meansand then fuel-air compression through 360* of shaft rotation while thesecond rotor is providing in sequence fuel-air combustion and thencombustion products exhaust through the exhaust valve means and then thesequence is reversed during two complete revolutions of each rotor. 2.The rotary engine of claim 1 wherein the surfaces in the housing arecylindrically shaped.
 3. The rotary engine of claim 1 wherein theignition means openings are adapted for spark plugs.
 4. The rotaryengine of claim 1 wherein the rotors have a cylindrical cross-section.5. The rotary engine of claim 2 wherein there are six sliding abutmentsso as to provide six sealed compartments around each rotor.
 6. Therotary engine of claim 1 wherein the driven gears are journaled byopposing outside portions of the housing.
 7. In a rotary engine usingtwo identically shaped rotors eccentrically mounted on a common shaft intwo separate housings with the maximum eccentricity spaced 180* fromeach other; at least two sliding abutments resiliently mounted in eachof the housings for continuous contact with the rotors throughout therevolution of the shaft so as to form sealed compression and thencombustion chambers with the rotors; and fuel-air ignition means in eachcompression combustion chamber wherein during operation each of thechambers on one of the rotors is providing in sequence a fuel-airmixture through an inlet valved conduit means and then fuel-aircompression through 360* of rotation while the other of the rotors isproviding in sequence fuel-air combustion and then combustion productsexhaust through an exhaust valved conduit means through a second 360* ofrotation, wherein the inlet and exhaust valves have a shaft extendingthrough and from the housing and wherein means for actuating the valvesat the extension of the shaft from the housing is provided to open thevalves the improvement which comprises: a. means for actuating the valveshafts including cam actuated levers mounted on the housing so as topivot anD depress each valve shaft in sequence; and b. four cam surfacescamming the levers for independent inlet and outlet valve opening aroundeach rotor which are mounted between the rotors and geared to the shaftso as to rotate at one-half the rate of rotation of the rotor shaft,wherein the cam surface rotation is regulated by the rotation of theshaft by means which drive a ring bearing the cam surfaces.
 8. Therotary engine of claim 7 wherein the cam surface rotation is regulatedby a driving gear mounted on the shaft and multiple driven gearsrotatably mounted to drive a ring gear bearing the cam surfaces.
 9. Therotary engine of claim 7 wherein the driven gears are journaled byopposing outside portions of the housings.